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Back to Engines and Middleware

[SDL] Function never returns

Started by
6 comments, last by BrianJensen 12 years, 8 months ago
I am using SDL_mixer along with SDL to play music samples.

I have been dealing with this problem the last couple of months, sometimes Mix_OpenAudio() returns and sometime it doesn't.
It was pretty much random but now it just never returns, meaning it never even gets to my code.

This is pretty serious as without this line my program can't play audio any more.

Don't believe me? Check this out:
[media]
[/media]

What could I be doing wrong?

I have been struggling with this a while, what can I change to get this working?

Any ideas extremely appreciated!
Walker
If this post was helpful please +1 or like it !

Webstrand
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Have you tried calling Mix_Init? Mix_OpenAudio should do this automatically but if you use an old version I'm not sure if it's needed, and in that case it is probably better to upgrade.
Do this code run from the main thread? I know some SDL stuff on some platforms will not work if called from other threads.
If this doesn't help, make a small test case! Then it is a good chance that you will find the problem by yourself. If not, you can post it here and we can help you.
I am using the current SDL_mixer 1.2.11, and yes it's running from the main thread.

Thanks,It does work in another project, so it's something specific to this project.

I'll make a test case and see if it works.
If this post was helpful please +1 or like it !

Webstrand
[size="5"]Test Results
With a small test program it still does the same thing.
I just don't understand.
Someone please tell my why this doesn't work as I can't continue until this is fixed.
Thanks,
Walker

[size="5"]H264 Lossless video of debugging
webStrandText2.png
-3.37MB
-H264 Lossless
-MKV format

[size="5"]Youtube Video of debugging
Here is a new video Youtube:
[media]
[/media]
(This video was crystal clear but Youtube screwed it up)

[size="5"]Source Code

/*This source code copyrighted by Lazy Foo' Productions (2004-2011)
and may not be redestributed without written permission.*/

//The headers
#include "SDL.h"
#include "SDL_image.h"
#include "SDL_ttf.h"
#include "SDL_mixer.h"
#include <string>

//Screen attributes
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;
const int SCREEN_BPP = 32;

//The surfaces
SDL_Surface *background = NULL;
SDL_Surface *message = NULL;
SDL_Surface *screen = NULL;

//The event structure
SDL_Event event;

//The font
TTF_Font *font = NULL;

//The color of the font
SDL_Color textColor = { 0, 0, 0 };

//The music that will be played
Mix_Music *music = NULL;

//The sound effects that will be used
Mix_Chunk *scratch = NULL;
Mix_Chunk *high = NULL;
Mix_Chunk *med = NULL;
Mix_Chunk *low = NULL;

SDL_Surface *load_image( std::string filename )
{
//The image that's loaded
SDL_Surface* loadedImage = NULL;

//The optimized surface that will be used
SDL_Surface* optimizedImage = NULL;

//Load the image
loadedImage = IMG_Load( filename.c_str() );

//If the image loaded
if( loadedImage != NULL )
{
//Create an optimized surface
optimizedImage = SDL_DisplayFormat( loadedImage );

//Free the old surface
SDL_FreeSurface( loadedImage );

//If the surface was optimized
if( optimizedImage != NULL )
{
//Color key surface
SDL_SetColorKey( optimizedImage, SDL_SRCCOLORKEY, SDL_MapRGB( optimizedImage->format, 0, 0xFF, 0xFF ) );
}
}

//Return the optimized surface
return optimizedImage;
}

void apply_surface( int x, int y, SDL_Surface* source, SDL_Surface* destination, SDL_Rect* clip = NULL )
{
//Holds offsets
SDL_Rect offset;

//Get offsets
offset.x = x;
offset.y = y;

//Blit
SDL_BlitSurface( source, clip, destination, &offset );
}

bool init()
{
//Initialize all SDL subsystems
if( SDL_Init( SDL_INIT_EVERYTHING ) == -1 )
{
return false;
}

//Set up the screen
screen = SDL_SetVideoMode( SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, SDL_SWSURFACE );

//If there was an error in setting up the screen
if( screen == NULL )
{
return false;
}

//Initialize SDL_ttf
if( TTF_Init() == -1 )
{
return false;
}

//Initialize SDL_mixer
if( Mix_OpenAudio( 22050, MIX_DEFAULT_FORMAT, 2, 4096 ) == -1 )
{
return false;
}

//Set the window caption
SDL_WM_SetCaption( "Monitor Music", NULL );

//If everything initialized fine
return true;
}

bool load_files()
{
//Load the background image
background = load_image( "background.png" );

//Open the font
font = TTF_OpenFont( "lazy.ttf", 30 );

//If there was a problem in loading the background
if( background == NULL )
{
return false;
}

//If there was an error in loading the font
if( font == NULL )
{
return false;
}

//Load the music
music = Mix_LoadMUS( "beat.wav" );

//If there was a problem loading the music
if( music == NULL )
{
return false;
}

//Load the sound effects
scratch = Mix_LoadWAV( "scratch.wav" );
high = Mix_LoadWAV( "high.wav" );
med = Mix_LoadWAV( "medium.wav" );
low = Mix_LoadWAV( "low.wav" );

//If there was a problem loading the sound effects
if( ( scratch == NULL ) || ( high == NULL ) || ( med == NULL ) || ( low == NULL ) )
{
return false;
}

//If everything loaded fine
return true;
}

void clean_up()
{
//Free the surfaces
SDL_FreeSurface( background );

//Free the sound effects
Mix_FreeChunk( scratch );
Mix_FreeChunk( high );
Mix_FreeChunk( med );
Mix_FreeChunk( low );

//Free the music
Mix_FreeMusic( music );

//Close the font
TTF_CloseFont( font );

//Quit SDL_mixer
Mix_CloseAudio();

//Quit SDL_ttf
TTF_Quit();

//Quit SDL
SDL_Quit();
}

int main( int argc, char* args[] )
{
//Quit flag
bool quit = false;

//Initialize
if( init() == false )
{
return 1;
}

//Load the files
if( load_files() == false )
{
return 1;
}

//Apply the background
apply_surface( 0, 0, background, screen );

//Render the text
message = TTF_RenderText_Solid( font, "Press 1, 2, 3, or 4 to play a sound effect", textColor );

//If there was an error in rendering the text
if( message == NULL )
{
return 1;
}

//Show the message on the screen
apply_surface( ( SCREEN_WIDTH - message->w ) / 2, 100, message, screen );

//Free the message
SDL_FreeSurface( message );

//Render the text
message = TTF_RenderText_Solid( font, "Press 9 to play or pause the music", textColor );

//If there was an error in rendering the text
if( message == NULL )
{
return 1;
}

//Show the message on the screen
apply_surface( ( SCREEN_WIDTH - message->w ) / 2, 200, message, screen );

//Free the message
SDL_FreeSurface( message );

//Render the text
message = TTF_RenderText_Solid( font, "Press 0 to stop the music", textColor );

//If there was an error in rendering the text
if( message == NULL )
{
return 1;
}

//Show the message on the screen
apply_surface( ( SCREEN_WIDTH - message->w ) / 2, 300, message, screen );

//Free the message
SDL_FreeSurface( message );

//Update the screen
if( SDL_Flip( screen ) == -1 )
{
return 1;
}

//While the user hasn't quit
while( quit == false )
{
//While there's events to handle
while( SDL_PollEvent( &event ) )
{
//If a key was pressed
if( event.type == SDL_KEYDOWN )
{
//If 1 was pressed
if( event.key.keysym.sym == SDLK_1 )
{
//Play the scratch effect
if( Mix_PlayChannel( -1, scratch, 0 ) == -1 )
{
return 1;
}
}
//If 2 was pressed
else if( event.key.keysym.sym == SDLK_2 )
{
//Play the high hit effect
if( Mix_PlayChannel( -1, high, 0 ) == -1 )
{
return 1;
}
}
//If 3 was pressed
else if( event.key.keysym.sym == SDLK_3 )
{
//Play the medium hit effect
if( Mix_PlayChannel( -1, med, 0 ) == -1 )
{
return 1;
}
}
//If 4 was pressed
else if( event.key.keysym.sym == SDLK_4 )
{
//Play the low hit effect
if( Mix_PlayChannel( -1, low, 0 ) == -1 )
{
return 1;
}
}
//If 9 was pressed
else if( event.key.keysym.sym == SDLK_9 )
{
//If there is no music playing
if( Mix_PlayingMusic() == 0 )
{
//Play the music
if( Mix_PlayMusic( music, -1 ) == -1 )
{
return 1;
}
}
//If music is being played
else
{
//If the music is paused
if( Mix_PausedMusic() == 1 )
{
//Resume the music
Mix_ResumeMusic();
}
//If the music is playing
else
{
//Pause the music
Mix_PauseMusic();
}
}
}
//If 0 was pressed
else if( event.key.keysym.sym == SDLK_0 )
{
//Stop the music
Mix_HaltMusic();
}
}
//If the user has Xed out the window
if( event.type == SDL_QUIT )
{
//Quit the program
quit = true;
}
}
}

//Free surfaces, fonts and sounds
//then quit SDL_mixer, SDL_ttf and SDL
clean_up();

return 0;
}
If this post was helpful please +1 or like it !

Webstrand
The code you pasted works for me. The code is identical to the lazyfoo's lesson 11 so it should not be anything wrong with that code.

The code you pasted works for me. The code is identical to the lazyfoo's lesson 11 so it should not be anything wrong with that code.


So what could be causing the problem?

I also:
Installed Visual Studio 2010
Downloaded the new SDL, SDL_mixer, SDL_image and SDL_ttf.
Compiled and linked in the new setup
Copied the new DLL's to the project directory and, it did the same thing!

What could be up with this?

(I let it run 21 minutes while not returning)
If this post was helpful please +1 or like it !

Webstrand
Make sure you don't have bad RAM in your computer. I know, seems random if you've never had that problem before.
I used to scoff whenever I heard people give that advice...sure enough when building SDL - only half of the examples would run. Certain stuff wouldn't compile in VS2010.

Long story short, tested RAM - had errors ...replaced and all was good.
http://www.memtest.org/
Download and burn.
boot from cd
Make sure you don't have bad RAM in your computer. I know, seems random if you've never had that problem before.
I used to scoff whenever I heard people give that advice...sure enough when building SDL - only half of the examples would run. Certain stuff wouldn't compile in VS2010.

Long story short, tested RAM - had errors ...replaced and all was good.
http://www.memtest.org/
Download and burn.
boot from cd
Make sure the audio type is valid and compatible with SDL before even bothering to check the ram, as it is more likely the cause.
You must not use AUDIO_S16, AUDIO_U16, AUDIO_S16LSB, or AUDIO_U16LSB.They are not portable, and SDL will not return an error code when they fail. The result will be a horrible staticy noise. You can usually use AUDIO_S16SYS, though not always. Future versions of SDL should take this parameter only as a hint, then read back the value that the OS (for example, OSS or ALSA) has chosen to use in case the desired audio type is not supported.
[/quote]
You should use "!= 0" instead of "== -1"

Comment out the part where the program actually plays file and just play nothing for all sound effects. See if the error still exists

Use while (!quit) rather than while (quit == false)

Sprite Creator 3 VX & XP

WARNING: I edit my posts constantly.

This topic is closed to new replies.

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